An infrastructure-based wireless network typically includes a communication network with fixed and wired gateways. Many infrastructure-based wireless networks employ a mobile unit or host which communicates with a fixed base station that is coupled to a wired network. The mobile unit can move geographically while it is communicating over a wireless link to the base station. When the mobile unit moves out of range of one base station, it may connect or “handover” to a new base station and starts communicating with the wired network through the new base station.
In comparison to infrastructure-based wireless networks, such as cellular networks or satellite networks, ad hoc networks are self-forming networks which can operate in the absence of any fixed infrastructure, and in some cases the ad hoc network is formed entirely of mobile nodes. An ad hoc network typically includes a number of geographically-distributed, potentially mobile units, sometimes referred to as “nodes,” which are wirelessly connected to each other by one or more links (e.g., radio frequency communication channels). The nodes can communicate with each other over a wireless media without the support of an infrastructure-based or wired network.
A wireless mesh network is a collection of wireless nodes or devices organized in a decentralized manner to provide range extension by allowing nodes to be reached across multiple hops. In a multi-hop network, communication packets sent by a source node can be relayed through one or more intermediary nodes before reaching a destination node. A large network can be realized using intelligent access points (IAP) which provide wireless nodes with access to a wired backhaul.
Wireless ad hoc networks can include both routable (meshed) nodes and non-routable (non-meshed) nodes. Meshed or “routable” nodes are devices which may follow a standard wireless protocol such as Institute of Electrical and Electronics Engineers (IEEE) 802.11s or 802.16j. These devices are responsible for forwarding packets to/from the proxy devices which are associated with them. Non-meshed or “non-routable” nodes are devices following a standard wireless protocol such as IEEE 802.11a, b, e, g or IEEE 802.15 but not participating in any kind of routing. These devices are “proxied” by meshed devices which establish routes for them.
As wireless communications networks become more prevalent, security continues to be a major concern to both communication network providers and end users. This is most evident when using a mobile wireless network where the security environment can offer the greatest challenges since data may be readily received and manipulated by many nodes. The radio links used in a wireless network expose the signaling and data traversing the network to eavesdroppers and/or would-be hackers. In a multi-hop wireless network, this requires each link in the meshed devices to have a unique security association established through the multi-hop authentication and key management process. Then, the air frames on the link can be protected with the established security associations.
Today's security solutions typically establish a security association between an authentication server and a node joining the network. Unfortunately, it can take ten seconds for the node to complete authentication with an authentication server. When a node joins an ad hoc network and establishes a secure link with one of its neighbors, it is advantageous to provide an accelerated security mechanism enabling secure links between the node and other neighboring nodes that are also members of the network quickly.
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